The cable as shown in Japanese Published Unexamined Patent Application No. H06-176626 is known as a conventional flexible cable. The cable is composed of a conductor formed by twisting annealed copper wires, an insulator, and a sheath. A conductive metallic thin film is formed on an inner surface of the sheath. However, while the cable is generally durable against breaking of the conductor, the cable is too rigid because of the emphasis on durability. Thus, flexibility is at a disadvantage.